My Principles for Building Software
A practitioner's list of principles for building software, most aimed at making systems simpler: make invalid states unrepresentable, enforce data consistency, design data before code, measure before trading away simplicity. The appendix shows what inconsistency costs — split two Boolean variables x and y that must stay equal into separate databases and the data gains two more states, leaving the toggle function with no correct answer. The author argues consistency is the most undervalued property in software engineering and that most bugs are data failing an expectation. Other principles: avoid trading local simplicity for global complexity (smaller services often do this), don't optimize without measurement, keep code consistent even when the consistent thing isn't the "correct" thing, and learn concepts — the relational model, algebraic data types, borrow checking — rather than surface details of React or Kubernetes. Aimed at backend and data engineers weighing service splits and schema design.